What Happens When You Roll a Natural 20 with Disadvantage?

As players of Dungeons & Dragons, we‘ve all had our share of memorable dice moments. That time you rolled a natural 20 on your death save and snatched victory from the jaws of defeat. Or when the Bard seduces a dragon with a perfect Persuasion check. But what if you roll that coveted natural 20 when you have disadvantage? Can you still pull off an epic feat against the odds?

In this guide, we‘ll dive deep into rolling critical hits with disadvantage – when they happen, the math behind them, and how we can make these unlikely dice stories more fun and exciting. Grab your twenty-siders, it‘s time to nerd out!

The Mechanics of Disadvantage

First, let‘s recap how disadvantage works mechanically in D&D 5th edition. When you have disadvantage on a d20 roll, you roll two d20s instead of one. You then note both results, and must use the lower number.

That lower die roll is what gets added to your modifiers to determine success or failure. Disadvantage represents circumstances that make success less likely, like attacking while blinded.

The opposite situation is advantage. With advantage, you also roll two d20s, but use the higher result. Advantage and disadvantage cancel each other out.

When a Natural 20 Still Fails

Here‘s the key fact about natural 20s with disadvantage: even if you roll a 20 on the first die, if the second die is lower, you must use the lower roll.

This means it‘s possible to roll a natural 20 and still fail! Some unlucky examples:

• You roll a 20, then a 15. You use the 15.
• You roll a natural 20, then a 2. You‘re forced to use the 2.
• In a miracle, you roll two nat 20s. You still only use one 20.

The natural 20 doesn‘t confer any special success, even though we love seeing those big numbers! Unless they also roll a 20, the player must use the lower roll according to the RAW rules.

The Long Odds of Rolling 20s with Disadvantage

While possible, rolling natural 20s with disadvantage is highly unlikely. Let‘s crunch the numbers:

• Normal chance to roll a natural 20: 5%
• Chance with disadvantage: 0.25%

With disadvantage, you‘re 20 times less likely to roll a 20 compared to a normal d20 roll! Here are the probabilities for each number on a d20 with disadvantage:

Roll	Normal Chance	Disadvantage Chance
1	5%	25%
20	5%	0.25%
10	5%	2.5%

As you can see, lower results become far more likely with disadvantage. It‘s a bitter feeling when you triumphantly roll a 20 only to have disadvantage force you to use a lower number!

Disadvantage Greatly Reduces Your Overall Odds of Success

Disadvantage doesn‘t just lower your chances of rolling natural 20s. It decreases your probability of success on any DC, not just 20.

For example, let‘s look at an attack roll with a +6 modifier, so you normally succeed on a 14 or higher. With disadvantage, the odds of hitting drop from 65% down to only 42.75%!

We can calculate the exact probabilities using the following formula:

((21 – DC) / 20) x ((21 – DC) / 20)

Plugging in the numbers shows just how much disadvantage impacts your overall success rate. For lower DCs like 10, it‘s less extreme but still significant. Disadvantage really punishes characters who rely on high dice results rather than flat bonuses.

Bounded Accuracy Makes Disadvantage Impactful

D&D 5th edition‘s bounded accuracy system also magnifies the impact of (dis)advantage.

With modifiers staying relatively low compared to previous editions, the d20 roll makes up a larger portion of the result. So disadvantage‘s effects of dragging down your dice values has more weight.

As one RPG Stack Exchange user put it:

"With bounded accuracy, (dis)advantage is king!"

House Rules for Natural 20s and Disadvantage

Some D&D groups use a house rule that natural 20s bypass disadvantage, scoring a critical hit anyway. There are reasonable cases on both sides here.

Arguments For This House Rule:

• Makes rolling a 20 more exciting, even with disadvantage
• Rewards unlikely good luck
• 20s feel special, so why not let them hit?

Reasons to Avoid This Rule:

• Messing with disadvantage reduces its impact
• More randomness, less consistency
• Not the RAW rules as written

In a poll on the DnD subreddit, over 65% of respondents said they use the natural 20 house rule. But roughly 35% still make 20s fail against disadvantage, so opinions are divided.

Ultimately it comes down to your group‘s preferences. Just be aware the RAW rules don‘t allow nat 20s to negate disadvantage.

When Advantage and Disadvantage Cancel Out

Importantly, advantage and disadvantage cancel each other out. If circumstances impose both advantage and disadvantage, they nullify and you simply make a normal d20 roll. For example:

• 1 source of advantage, 1 of disadvantage = normal roll
• 3 sources of advantage, 1 disadvantage = normal roll

The number of (dis)advantage sources doesn‘t matter. You don‘t ever end up rolling with both. They neutralize completely.

Two Rolls Where Disadvantage Really Hurts

While no one loves disadvantage, there are two rolls where it stings the most:

Attack Rolls

Scoring a critical hit on an attack roll (natural 20) allows you to double your damage dice. But with disadvantage, your chances of landing those brutal crits plummets. No one wants to have their epic new sword fail to impress!

Death Saving Throws

When making death saves to avoid dying, rolling a natural 20 instantly stabilizes you and heals 1 HP. Disadvantage makes this lifesaving 20 almost impossible to hit when you need it most!

Disadvantage in Virtual Tabletops

When playing D&D online using virtual tabletops like Roll20 or Fantasy Grounds, disadvantage is handled automatically:

• Roll20: When making a disadvantaged roll, it prompts you to click a second time to roll the second d20.

• D&D Beyond: Right click the d20 icon and select "Disadvantage". It rolls twice and takes the lower.

This removes any question around applying disadvantage correctly. The computer handles the math for you!

Creative Uses of Disadvantage as a DM

As Dungeon Masters, we have plenty of options to impose disadvantage on players. But take care not to overdo it, or the mechanic becomes more frustrating than fun. Here are some tips:

• Don‘t stick multiple PCs with disadvantage every single round – spread it out.

• Impose it situationally when fitting, not arbitrarily. Describe the circumstances causing it.

• Provide opportunities for PCs to creatively remove or cancel their disadvantage.

• Ensure NPCs face disadvantage when reasonable, not just the players.

Used judiciously, disadvantage increases drama without ruining the fun. But punish your players with it too often, and they‘ll quickly disengage.

The History of the Iconic d20

To understand disadvantage, we should briefly touch on the history of the quintessential D&D dice – the d20. Twenty-sided dice have actually existed for thousands of years in various geometric forms.

The icosahedron, a twenty-faced solid with equilateral triangles, dates back to ancient civilizations. But early versions never rolled truly randomly due to uneven shapes.

In the 1970s, the newly created Dungeons & Dragons made the d20 iconic by using it for core mechanics like ability checks. The modern carved d20 design enabled decent randomness while still being manufacturable.

Over many editions of D&D, this classic twenty-sided die has cemented its reputation as the heartbeat of RPG gameplay. Where would we be without the d20 to fuel our tales of natural 20s… or 1s?

Roller Stories of Nat 20s vs Disadvantage!

To add some flair, I asked D&D players across Reddit and Twitter to share their most memorable stories of rolling natural 20s with disadvantage! Here are some of the entertaining highlight recounts:

Sarah K. recalls:

"I was surrounded by enemies and made a break for it, rolling with disadvantage to tumble past them. By miracle I rolled double nat 20s! I gloated about my luck as my rogue danced to safety."

Meanwhile, Alex T. had the opposite experience:

"In a tense stand-off, I drew my bow against the evil king. My first attack roll was a natural 20! Then despair – the second roll was a measly 3. The table groaned as my useless critical miss went wild. Our final battle would be uphill from there…"

And who can forget the classic death save roller coaster, as Peter G describes:

"Facing down a lich, our party was almost wiped. Bleeding out, I rolled with disadvantage to cling to life, and somehow hit a natural 20! But in a twist of fate, the second roll was a 1. Just when I thought I‘d survived, disadvantage pulled the rug out…"

While we love the excitement when our 20-sided luck defies the odds, disadvantage keeps things interesting by making those moments of glory all the more sweet!

The Unlikely Critical Hits Live On

In this guide, we covered everything you need to know about rolling natural 20s with disadvantage – how it works rules-wise, the probabilities behind it, house rules players use, and stories of unlikely dice triumphs.

While the math shows critical hits are far less likely with disadvantage, we have to respect the dice gods when they smile upon us! May your adventures include many more improbable tales of nat 20s beating the odds. Just don‘t count on it – and watch out for those brutal 1s!